George s



(No Model.)

G. S. MAGLAURIN. SGAPFOLD SEGURING DEVICE.

No. 427,18Q. Patented May 6, 1890.

GEORGE S. MAOLAURIN, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR OF ONE-HALF TO JOHN H. ORANKSI-IAV, OF SAME PLACE.

SCAFFOLD-SECURING DEVICE.

SPECIFICATION forming part of Letters Patent No. 427,180, dated May 6, 1890.

Application filed November 25, 1889. Serial No. 331,425. (No model.)

To @ZZ whom t may concern:

Be it known that I, GEORGE S. MACLAU- RIN, of the city of Philadelphia and State of Pennsylvania, have invented a certain new and useful Improvement in Scaffold-Securing Devices; and I do hereby declare the following to be a full, clear, and eX-act description thereof, reference being had to the accompanying drawings, forming part of this specication.

My invention has relation to portable adjustable scaffolds having locking-plates for locking the cross-beams to the uprights, adaptedto engage with a fixed spur attached to the uprights; and it consists in a plate having an open oblong slot for the entrance of the neck of the fixed pin or spur, a sliding tongue 0r pawl extending across or partially across the slot, which pawl has an inclined under surface adapted to slide on the neck of the spur and t0 raise the said pawl when it comes in contact with the spur and to drop into its normal position when the spur is in position above the line of contact with the point of the pawl. The pawl falling, thereby engages the spur and secures the cross-beam Xedly to the upright.

In the accompanying drawings similar letters of reference refer to similar parts throughout.

Figure 1 is a front elevation of the uprights and cross-braces of a scaffold in position. Fig. 2 shows a section of a cross-beam locked to the upright, with the brace out away to show the improved locking device, on the line y y of Fig. 4. Fig. 3 shows the pawl of the .brace-lock raised by the spur as in the act of securing the brace on the spur, and at the point just before the pawl falls and locks, also cut away. Fig. 4 is a cross-sectional view of the upright and cross-brace shown in Fig. 2, on the line w Vw of Fig. l. Fig. 5 is a partially sectional view on the line z z of Fig. 6, of fixed locking-plate adjusted to the other end of the broken brace shown in Fig. 2 and secured to the fixed spur. Fig. 6 is a crosssection of Fig. 5, on the line xm of Fig. l. Fig. 7 is my improved securing device detached in perspective.

A A represent the uprights, to which are affixed the headed spurs c.

B B are the braces, to which are affixed at one end the securing-plates b, each having an oblong or elliptical opening therein at an oblique angle to the line of the brace,l which is adapted to engage with the horizontal spur a. At the other end of the brace B is my improved locking-plate O. After the lockingplate b at the end of the brace B has been secured to the spur o, on the upright A', by placing it at the proper angle, the slot e in the locking-plate C, affixed at the other end of the brace B, is passed down over the neck of the spur (1J-cn the upright A, which may be at the desired position. As the plate C is pressed down, the pawl p, the normal position of which is across or partially across the slot c of its own gravity or by a spring, is forced up by its inclined lower edge coming in contact with the neck of the spur until the point shown in Fig. 3 is passed, when of its own gravity or by a spring device, if desired, it again falls and secures the spur a, as in the position shown in Fig. 2. An elliptical-shaped slot s is provided in the plate C,-as shown, through which a squared pin passes secured to the pawl p on one end and riveted to a head H on the other end, allowing the pawl p thus to pass freely up and down in a line described by the elliptical-shaped slot s.

A rest r is secured to the plate O to prevent the pawl p from dropping too far down. As shown in the cross-section, Fig. 4, the plate O is secured to or sunk in the brace B. An

opening or recess z5 is provided in the brace 85 B for the head of the spur a and the accommodation of the pawl p, the neck of the spur a, from its head to the surface-line of the upright A, being about equal in length to the thickness of the plate C and the pawl p. A recess g is likewise provided in the brace B under the plate b, as shown in Fig 6, for the accommodation of the head of the spur a.

It is preferable to attach the securing-plates to the inner side of the brace B rather than to the outer side, as described, as the necessity for an awkward and unnecessarily long spur a is thus obviated. The securing-plates are fastened to the brace B by screws or any other suitable means.

I am aware that securing-plates of other constructions for scaffolds have been known IOO and used. These I do not broadly claim; but

my invention consists in the constructionV herein particularly set forth.

I-Iavingthus described my invention, WhatI claim, and desire to secure by Letters Patent, 1s-

In portable scaffolds, in combination With a Xed spur, a locking-plate having an oblong j open slot for the entrance of the neck of the spur, a sliding tongue or paWl extending across or partially across the slot and adapted i to slide away automatically from the line of the vertical slot when the neck of the spur set forthv and` described. 

